1. Field of the Invention
The present invention is in the field of medical equipment and more specifically relates to an apparatus for raising a patient's leg to an elevated position above the bed, for maintaining the leg in the elevated position, and for lowering the leg to the surface of the bed, all the while holding the leg in a chosen degree of abduction, fixed external rotation, and minimum flexion.
2. Some Definitions
As illustrated in the diagram of FIG. 12, FLEXION (F) is motion involving an increase of the angle between two bones at a joint. EXTENSION is the opposite of flexion and involves a decrease in the angle between the two bones.
In INTERNAL ROTATION (IR) the toes of the foot are turned inward as shown in the diagram of FIG. 13. In EXTERNAL ROTATION (ER) the toes are turned outward.
In ABDUCTION (AB) the leg is moved away from the midline of the body, as shown in the diagram of FIG. 14. The opposite of abduction is ADDUCTION (AD), in which the leg is moved toward the midline of the body.
ARTHROPLASTY is the artificial replacement of part or all of a joint surface.
3. The Prior Art
The human pelvis includes two ball-and-socket hip joints, right and left. The affected side is replaced to remedy severe conditions such as arthritis or because of bone fracture. Following such replacement surgery, the patient must avoid both adduction (the opposite of abduction) and internal rotation of the affected leg to prevent dislocation of the replaced hip joint. It is also essential that flexion of the affected hip and corresponding knee be minimized.
To prevent these dangerous movements from occurring, it has been conventional in the art to place a large thick triangular pillow 202 such as that shown in FIG. 15 between the patient's legs, as shown in FIG. 16, and to strap the legs against opposite sides 204 of the pillow by use of the straps 206, 208, 210, 212 which may be secured by VELCRO.RTM. fasteners of which the pieces 214, 216 are typical.
Proper management of post operative patients requires patient movement, positioning and skin care. Without these, lung, circulatory, and skin problems may develop. Proper skin care includes eliminating pressure from high risk areas of the body. The most prominent of these areas are the heel, sacrum, buttocks, and greater trochanter (side of hips) regions. If pressure is not removed several times a day decubiti will surely result. Most hip arthroplasties occur in people over the age of 60.
Thus proper management of the post-operative hip arthroplasty patient is highly complicated by the necessity of maintaining an abducted, externally rotated and minimally flexed position. Because the opposite of these movements are the most commonly assumed positions of people in bed, maintaining correct alignment of hip arthroplasties has been a difficult challenge since its beginning. The acute post-operative course lasts two to three weeks on the average.
Although the abductor pillow of FIGS. 15 and 16 was an easy and obvious method of caring for these patients, it has turned out to be far too simplistic and has actually created more problems than it has solved. Thus, it has now been abandoned by many hospitals and teaching facilities, and they have resorted to using standard pillows and literally hoping for the best.
The major inadequacies and dangers of the abductor pillow of FIGS. 15 and 16 are:
1. The pillow totally confines the uninvolved leg, which is unnecessary and complicates patient care.
2. Since the uninvolved leg is not painful, patients move it continuously and therefore pull the involved leg into flexed and adducted positions whenever the uninvolved leg moves into flexion or abduction.
3. The abductor pillow in no way restricts internal rotation or flexion of the involved hip. It also does not restrict in any way knee flexion which is crucial in preventing hip movement.
4. When rotation of the body toward the unaffected side is attempted there is no way of maintaining the body in this position other than propping pillows behind the entire length of the body. It must be remembered that with the pillow the affected foot sits about 18-24 inches off the bed. It is obvious how this position would be very difficult to maintain in an object which is motionless much less a person who is trying to move all the time.
5. While rotated to the side for 1 to 2 hours, 3 to 4 times a day, it has been impossible to prevent the patient from bending his knee. When this happens his hip flexes also, and since internal rotation has not been eliminated, dislocation of the affected hip frequently occurs. Constant patient surveillance by nursing staff would be the only way to prevent this occurrence and that is literally impossible.
6. While rotated, the uninvolved hip bears all the weight of the abductor pillow and the involved leg, and it also is immobilized if proper positioning is maintained. This patient discomfort is totally unnecessary.
7. In a supine or rotated position the straps on the pillow must be tight to prevent movement. This causes a high risk of peroneal nerve palsy which results in permanent foot drop, requiring a permanent short leg brace to correct. Peroneal nerve palsy results from excessive pressure to the nerve as it becomes very superficial at the outside aspect of the knee.
8. While rotated toward the uninvolved side the patient pulls the uninvolved leg forward in the effort to get comfortable. When this happens it pulls the involved leg downward to an adducted position, therefore without any degree of abduction and no prevention of internal rotation, dislocation frequently occurs during this attempted maneuver.
9. Use of the abductor pillow requires at least 2 nurses and frequently 3 or 4 to do the rotating maneuver, which is very difficult to organize in an acute hospital setting.
10. The abductor pillow requires the use of 4 to 6 pillows to maintain a rotated position. Storage of this many pillows is difficult in a patient's room. Also, and very importantly, these pillows become contaminated while not in use and usually are stacked in a chair because they fall and frequently get used by other patients in the meantime. Thus the risk of infection is greatly increased.
11. The abductor pillow invites decubiti, especially on both heels, sacrum and the buttocks. It actually promotes them on the heels because the weight of the pillow pulls the heels into the bed further.
Various workers in the art have proposed apparatus other than the conventional abductor pillow for treating hip dislocations. In U.S. Pat. No. 3,759,252, Berman shows an apparatus for treating hip dislocations in which the patient lies in a cradle shell with his knees held in an elevated position by a support bar which is adjustable in position to permit selection of the degree of flexion, which is maintained by the apparatus. The apparatus also includes a support yoke assembly for engaging about the top side of the patient's leg to secure the legs in a fixed degree of abduction. The apparatus of Berman includes no provision for rotating the patient onto his side.
In U.S. Pat. No. 3,815,589, Bosley describes a brace assembly for controlling the hip position of a child. The assembly includes a pair of thigh cuffs and a pair of calf cuffs, each cuff being generally semicircular in shape and suitably padded. The thighs of the child are positioned within the thigh cuffs and the calves are also fastened into their cuffs. The thigh and calf cuffs can be selectively rotated to desired orientations and locked in the desired orientations. The brace assembly allows for a variety of positions of the hip including abduction, external and internal rotation and some degree of flexion. There is little if any structural similarity between the apparatus of Bosley and that of the present invention.
In U.S. Pat. No. 3,730,177, Thum shows a device in which the motion of the patient's legs is yieldably opposed by tension belts or spring elements. The device does not hold the patient's calf and it is clear that the device produces flexion instead of avoiding it.
None of these workers in the prior art has addressed the problem of rotating the patient onto his side while maintaining a desired degree of abduction and external rotation and minimal flexion. As will be seen below, the apparatus of the present invention overcomes the difficulties associated with use of the conventional abductor pillow and provides a means for rotating the patient onto his side that is both safe and convenient.